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Diffstat (limited to 'drivers/watchdog/alim7101_wdt.c')
-rw-r--r--drivers/watchdog/alim7101_wdt.c451
1 files changed, 451 insertions, 0 deletions
diff --git a/drivers/watchdog/alim7101_wdt.c b/drivers/watchdog/alim7101_wdt.c
new file mode 100644
index 000000000..4ff7f5afb
--- /dev/null
+++ b/drivers/watchdog/alim7101_wdt.c
@@ -0,0 +1,451 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ALi M7101 PMU Computer Watchdog Timer driver
+ *
+ * Based on w83877f_wdt.c by Scott Jennings <linuxdrivers@oro.net>
+ * and the Cobalt kernel WDT timer driver by Tim Hockin
+ * <thockin@cobaltnet.com>
+ *
+ * (c)2002 Steve Hill <steve@navaho.co.uk>
+ *
+ * This WDT driver is different from most other Linux WDT
+ * drivers in that the driver will ping the watchdog by itself,
+ * because this particular WDT has a very short timeout (1.6
+ * seconds) and it would be insane to count on any userspace
+ * daemon always getting scheduled within that time frame.
+ *
+ * Additions:
+ * Aug 23, 2004 - Added use_gpio module parameter for use on revision a1d PMUs
+ * found on very old cobalt hardware.
+ * -- Mike Waychison <michael.waychison@sun.com>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/types.h>
+#include <linux/timer.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/ioport.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/pci.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+
+
+#define WDT_ENABLE 0x9C
+#define WDT_DISABLE 0x8C
+
+#define ALI_7101_WDT 0x92
+#define ALI_7101_GPIO 0x7D
+#define ALI_7101_GPIO_O 0x7E
+#define ALI_WDT_ARM 0x01
+
+/*
+ * We're going to use a 1 second timeout.
+ * If we reset the watchdog every ~250ms we should be safe. */
+
+#define WDT_INTERVAL (HZ/4+1)
+
+/*
+ * We must not require too good response from the userspace daemon.
+ * Here we require the userspace daemon to send us a heartbeat
+ * char to /dev/watchdog every 30 seconds.
+ */
+
+#define WATCHDOG_TIMEOUT 30 /* 30 sec default timeout */
+/* in seconds, will be multiplied by HZ to get seconds to wait for a ping */
+static int timeout = WATCHDOG_TIMEOUT;
+module_param(timeout, int, 0);
+MODULE_PARM_DESC(timeout,
+ "Watchdog timeout in seconds. (1<=timeout<=3600, default="
+ __MODULE_STRING(WATCHDOG_TIMEOUT) ")");
+
+static int use_gpio; /* Use the pic (for a1d revision alim7101) */
+module_param(use_gpio, int, 0);
+MODULE_PARM_DESC(use_gpio,
+ "Use the gpio watchdog (required by old cobalt boards).");
+
+static void wdt_timer_ping(struct timer_list *);
+static DEFINE_TIMER(timer, wdt_timer_ping);
+static unsigned long next_heartbeat;
+static unsigned long wdt_is_open;
+static char wdt_expect_close;
+static struct pci_dev *alim7101_pmu;
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout,
+ "Watchdog cannot be stopped once started (default="
+ __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+/*
+ * Whack the dog
+ */
+
+static void wdt_timer_ping(struct timer_list *unused)
+{
+ /* If we got a heartbeat pulse within the WDT_US_INTERVAL
+ * we agree to ping the WDT
+ */
+ char tmp;
+
+ if (time_before(jiffies, next_heartbeat)) {
+ /* Ping the WDT (this is actually a disarm/arm sequence) */
+ pci_read_config_byte(alim7101_pmu, 0x92, &tmp);
+ pci_write_config_byte(alim7101_pmu,
+ ALI_7101_WDT, (tmp & ~ALI_WDT_ARM));
+ pci_write_config_byte(alim7101_pmu,
+ ALI_7101_WDT, (tmp | ALI_WDT_ARM));
+ if (use_gpio) {
+ pci_read_config_byte(alim7101_pmu,
+ ALI_7101_GPIO_O, &tmp);
+ pci_write_config_byte(alim7101_pmu,
+ ALI_7101_GPIO_O, tmp | 0x20);
+ pci_write_config_byte(alim7101_pmu,
+ ALI_7101_GPIO_O, tmp & ~0x20);
+ }
+ } else {
+ pr_warn("Heartbeat lost! Will not ping the watchdog\n");
+ }
+ /* Re-set the timer interval */
+ mod_timer(&timer, jiffies + WDT_INTERVAL);
+}
+
+/*
+ * Utility routines
+ */
+
+static void wdt_change(int writeval)
+{
+ char tmp;
+
+ pci_read_config_byte(alim7101_pmu, ALI_7101_WDT, &tmp);
+ if (writeval == WDT_ENABLE) {
+ pci_write_config_byte(alim7101_pmu,
+ ALI_7101_WDT, (tmp | ALI_WDT_ARM));
+ if (use_gpio) {
+ pci_read_config_byte(alim7101_pmu,
+ ALI_7101_GPIO_O, &tmp);
+ pci_write_config_byte(alim7101_pmu,
+ ALI_7101_GPIO_O, tmp & ~0x20);
+ }
+
+ } else {
+ pci_write_config_byte(alim7101_pmu,
+ ALI_7101_WDT, (tmp & ~ALI_WDT_ARM));
+ if (use_gpio) {
+ pci_read_config_byte(alim7101_pmu,
+ ALI_7101_GPIO_O, &tmp);
+ pci_write_config_byte(alim7101_pmu,
+ ALI_7101_GPIO_O, tmp | 0x20);
+ }
+ }
+}
+
+static void wdt_startup(void)
+{
+ next_heartbeat = jiffies + (timeout * HZ);
+
+ /* We must enable before we kick off the timer in case the timer
+ occurs as we ping it */
+
+ wdt_change(WDT_ENABLE);
+
+ /* Start the timer */
+ mod_timer(&timer, jiffies + WDT_INTERVAL);
+
+ pr_info("Watchdog timer is now enabled\n");
+}
+
+static void wdt_turnoff(void)
+{
+ /* Stop the timer */
+ del_timer_sync(&timer);
+ wdt_change(WDT_DISABLE);
+ pr_info("Watchdog timer is now disabled...\n");
+}
+
+static void wdt_keepalive(void)
+{
+ /* user land ping */
+ next_heartbeat = jiffies + (timeout * HZ);
+}
+
+/*
+ * /dev/watchdog handling
+ */
+
+static ssize_t fop_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ /* See if we got the magic character 'V' and reload the timer */
+ if (count) {
+ if (!nowayout) {
+ size_t ofs;
+
+ /* note: just in case someone wrote the magic character
+ * five months ago... */
+ wdt_expect_close = 0;
+
+ /* now scan */
+ for (ofs = 0; ofs != count; ofs++) {
+ char c;
+ if (get_user(c, buf + ofs))
+ return -EFAULT;
+ if (c == 'V')
+ wdt_expect_close = 42;
+ }
+ }
+ /* someone wrote to us, we should restart timer */
+ wdt_keepalive();
+ }
+ return count;
+}
+
+static int fop_open(struct inode *inode, struct file *file)
+{
+ /* Just in case we're already talking to someone... */
+ if (test_and_set_bit(0, &wdt_is_open))
+ return -EBUSY;
+ /* Good, fire up the show */
+ wdt_startup();
+ return stream_open(inode, file);
+}
+
+static int fop_close(struct inode *inode, struct file *file)
+{
+ if (wdt_expect_close == 42)
+ wdt_turnoff();
+ else {
+ /* wim: shouldn't there be a: del_timer(&timer); */
+ pr_crit("device file closed unexpectedly. Will not stop the WDT!\n");
+ }
+ clear_bit(0, &wdt_is_open);
+ wdt_expect_close = 0;
+ return 0;
+}
+
+static long fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ void __user *argp = (void __user *)arg;
+ int __user *p = argp;
+ static const struct watchdog_info ident = {
+ .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT
+ | WDIOF_MAGICCLOSE,
+ .firmware_version = 1,
+ .identity = "ALiM7101",
+ };
+
+ switch (cmd) {
+ case WDIOC_GETSUPPORT:
+ return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
+ case WDIOC_GETSTATUS:
+ case WDIOC_GETBOOTSTATUS:
+ return put_user(0, p);
+ case WDIOC_SETOPTIONS:
+ {
+ int new_options, retval = -EINVAL;
+
+ if (get_user(new_options, p))
+ return -EFAULT;
+ if (new_options & WDIOS_DISABLECARD) {
+ wdt_turnoff();
+ retval = 0;
+ }
+ if (new_options & WDIOS_ENABLECARD) {
+ wdt_startup();
+ retval = 0;
+ }
+ return retval;
+ }
+ case WDIOC_KEEPALIVE:
+ wdt_keepalive();
+ return 0;
+ case WDIOC_SETTIMEOUT:
+ {
+ int new_timeout;
+
+ if (get_user(new_timeout, p))
+ return -EFAULT;
+ /* arbitrary upper limit */
+ if (new_timeout < 1 || new_timeout > 3600)
+ return -EINVAL;
+ timeout = new_timeout;
+ wdt_keepalive();
+ }
+ fallthrough;
+ case WDIOC_GETTIMEOUT:
+ return put_user(timeout, p);
+ default:
+ return -ENOTTY;
+ }
+}
+
+static const struct file_operations wdt_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .write = fop_write,
+ .open = fop_open,
+ .release = fop_close,
+ .unlocked_ioctl = fop_ioctl,
+ .compat_ioctl = compat_ptr_ioctl,
+};
+
+static struct miscdevice wdt_miscdev = {
+ .minor = WATCHDOG_MINOR,
+ .name = "watchdog",
+ .fops = &wdt_fops,
+};
+
+static int wdt_restart_handle(struct notifier_block *this, unsigned long mode,
+ void *cmd)
+{
+ /*
+ * Cobalt devices have no way of rebooting themselves other
+ * than getting the watchdog to pull reset, so we restart the
+ * watchdog on reboot with no heartbeat.
+ */
+ wdt_change(WDT_ENABLE);
+
+ /* loop until the watchdog fires */
+ while (true)
+ ;
+
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block wdt_restart_handler = {
+ .notifier_call = wdt_restart_handle,
+ .priority = 128,
+};
+
+/*
+ * Notifier for system down
+ */
+
+static int wdt_notify_sys(struct notifier_block *this,
+ unsigned long code, void *unused)
+{
+ if (code == SYS_DOWN || code == SYS_HALT)
+ wdt_turnoff();
+
+ return NOTIFY_DONE;
+}
+
+/*
+ * The WDT needs to learn about soft shutdowns in order to
+ * turn the timebomb registers off.
+ */
+
+static struct notifier_block wdt_notifier = {
+ .notifier_call = wdt_notify_sys,
+};
+
+static void __exit alim7101_wdt_unload(void)
+{
+ wdt_turnoff();
+ /* Deregister */
+ misc_deregister(&wdt_miscdev);
+ unregister_reboot_notifier(&wdt_notifier);
+ unregister_restart_handler(&wdt_restart_handler);
+ pci_dev_put(alim7101_pmu);
+}
+
+static int __init alim7101_wdt_init(void)
+{
+ int rc = -EBUSY;
+ struct pci_dev *ali1543_south;
+ char tmp;
+
+ pr_info("Steve Hill <steve@navaho.co.uk>\n");
+ alim7101_pmu = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101,
+ NULL);
+ if (!alim7101_pmu) {
+ pr_info("ALi M7101 PMU not present - WDT not set\n");
+ return -EBUSY;
+ }
+
+ /* Set the WDT in the PMU to 1 second */
+ pci_write_config_byte(alim7101_pmu, ALI_7101_WDT, 0x02);
+
+ ali1543_south = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533,
+ NULL);
+ if (!ali1543_south) {
+ pr_info("ALi 1543 South-Bridge not present - WDT not set\n");
+ goto err_out;
+ }
+ pci_read_config_byte(ali1543_south, 0x5e, &tmp);
+ pci_dev_put(ali1543_south);
+ if ((tmp & 0x1e) == 0x00) {
+ if (!use_gpio) {
+ pr_info("Detected old alim7101 revision 'a1d'. If this is a cobalt board, set the 'use_gpio' module parameter.\n");
+ goto err_out;
+ }
+ nowayout = 1;
+ } else if ((tmp & 0x1e) != 0x12 && (tmp & 0x1e) != 0x00) {
+ pr_info("ALi 1543 South-Bridge does not have the correct revision number (???1001?) - WDT not set\n");
+ goto err_out;
+ }
+
+ if (timeout < 1 || timeout > 3600) {
+ /* arbitrary upper limit */
+ timeout = WATCHDOG_TIMEOUT;
+ pr_info("timeout value must be 1 <= x <= 3600, using %d\n",
+ timeout);
+ }
+
+ rc = register_reboot_notifier(&wdt_notifier);
+ if (rc) {
+ pr_err("cannot register reboot notifier (err=%d)\n", rc);
+ goto err_out;
+ }
+
+ rc = register_restart_handler(&wdt_restart_handler);
+ if (rc) {
+ pr_err("cannot register restart handler (err=%d)\n", rc);
+ goto err_out_reboot;
+ }
+
+ rc = misc_register(&wdt_miscdev);
+ if (rc) {
+ pr_err("cannot register miscdev on minor=%d (err=%d)\n",
+ wdt_miscdev.minor, rc);
+ goto err_out_restart;
+ }
+
+ if (nowayout)
+ __module_get(THIS_MODULE);
+
+ pr_info("WDT driver for ALi M7101 initialised. timeout=%d sec (nowayout=%d)\n",
+ timeout, nowayout);
+ return 0;
+
+err_out_restart:
+ unregister_restart_handler(&wdt_restart_handler);
+err_out_reboot:
+ unregister_reboot_notifier(&wdt_notifier);
+err_out:
+ pci_dev_put(alim7101_pmu);
+ return rc;
+}
+
+module_init(alim7101_wdt_init);
+module_exit(alim7101_wdt_unload);
+
+static const struct pci_device_id alim7101_pci_tbl[] __used = {
+ { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533) },
+ { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
+ { }
+};
+
+MODULE_DEVICE_TABLE(pci, alim7101_pci_tbl);
+
+MODULE_AUTHOR("Steve Hill");
+MODULE_DESCRIPTION("ALi M7101 PMU Computer Watchdog Timer driver");
+MODULE_LICENSE("GPL");
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